Engine failure survey

[Channel Ribs]

It has been suggested elsewhere that second hand engines are more prone to critical failure at sea than new ones, irrespective of fuel system or electrical installation.

What are Ribbers experiences with engine's letting them down when on the water?

[biffer]

Being an inboard man I find that outboards break down at anytime. To me they aren't built robust enough

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[PeterM]

Now thats a good question !! I've often wondered how 'unreliable' engines really are ...

I have been lucky enough to run new motors except a 200 opti, of a few years old. Every engine I have owned ( 8 in all some 2s some 4s) got me home. Only the opti ever hiccuped with a power loss but I still 'managed' 25knts for the 10 miles home.

I think all depends on how they are looked after.

Always exceptions to the rule - look at Martinis engine , looked after but still went pop.

Oh I forgot the Suzuki that died right in the entrance to Portsmouth in 1991 ....I was popular!.......but it wasn't my boat ( an Sr4 with a 1985 motor)

[Mollers]

The 10yo Opti on my 6.5 Vipermax (now owned by Spittle123), never missed a beat.

I've had a couple of large inboards, they don't suffer from the niggly faults as with outboards, they fail in big lumps.

Transmission is/was a weak area with inboards. Lots of hp and torque going through 90 degrees twice.

[Nos4r2]

Depends how old you're talking. I've had a gearbox let go, but it was on an absolutely ancient Johnson.

I think it's entirely dependant on which engine it is,the previous owner,how well it's been maintained and how many hours it's done.

Oh, and luck-not whether the engine is new or not.

[Channel Ribs]

Originally Posted by Nos4r2

Depends how old you're talking.

I am hoping that people can recall examples, so we can build up an understanding.

[wavelength]

Volvo penta 35-bought new splined drive on crankshaft stripped eventually miles out to sea requiring some carefully worded conversations with a friend to tow it back

mariner 40-the old two cylinder yammie one-bought new never missed a beat over 15 years and still going strong when we sold the boat on. Brilliant!

New Merc 90 four stroke 2001. Oil pump seals failed at 3 weeks old in entrance to poole with chain ferry behind on an ebbing tide, an onshore wind and a seacat approaching. I said "golly gosh" or something similar. After some "discussions" with Sowesters it was replaced and allegedly all motors recalled for a fix but I have met others with mariner/mercs 75/90 with same problem. Replacement motor developed knocking noise months later which was found to be flywheel loose!!!!! Last of the carb models it had float valve sticking problems thru lack of use but is now run by a friend and is fine- been better for being used.

Merc 50 4 stroke new in 2003 ish absolutely fine when I had it but has since had the grommet replaced between head and leg where the cooling water goes as my mechanic said when we bought it that it would eventually as they have "prostrate" problems.

Suzuki 90 four stroke 2006 ish bought new and has been faultless so far (except needed replacement trim sender unit at silly money) which is probably the kiss of death for it!

[gotchiguy]

Originally Posted by PeterM

Always exceptions to the rule - look at Martinis engine , looked after but still went pop.

Obviously he takes fantastic care of them, but they were bought for a relative pittance from the States as unseen, and he has had a number of issues with them over the years. I seem to remember him telling us they had been flooded? Or that may just be my imagination.

[biffer]

outboards seem to fail at anytime no matter how well they're looked after, and it's never the same thing, compressor pumps or melted piston etc, it just happens, inboards fail when they are neglected or not used, but its usually the marine bits on an inboard that fail, water jackets, pumps, dodgey fuel, etc

[Channel Ribs]

Originally Posted by biffer

compressor pumps or melted piston etc

Can you remember any rough ages or makes Biff?

[martini]

Originally Posted by gotchiguy

Obviously he takes fantastic care of them, but they were bought for a relative pittance from the States as unseen, and he has had a number of issues with them over the years. I seem to remember him telling us they had been flooded? Or that may just be my imagination.

Your imagination.
As far as opti's go, it's suggested that they are ok for weekend warriors putting 50 hours pa on them but certain things are inevitable eg compressors.

It's when they're subjected to more work ie commercial/me that the problems start. Merc like to push Verados at this sector of the market, they get less comebacks.

All the problems I've had are unrelated and on both engines so the finger can't be pointed anywhere except it's not the best designed/built motor for reliability.

I'd never have another big outboard powered boat, as Biffer says, they're all prone to breakages and with the way petrol prices are going it's tipped the scales in favour of diesel inboards.

There are some good outdrives around that can handle the torque, Konrads for one albeit for a premium.

[biffer]

They have fixed the problem with upload from iPhone. Sorry to hijack your thread with a pic. Carry on

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[jezza2011]

Hmm I have a Mariner 75 ELPTO cerca 1991.
It 20 years old and never let me down out at sea.
But has had some minor problems.

I always run the engine up before I take it anywhere.
Its never let me down.

its had
1x alarm unit
1x fuel pump diaphrams
1x stator coil.
a few impellas and a few sets of plugs.

so not too bad realy.
Its never broken down or failed to start.
so from my prespective my 75 hp Mariner ELPTO long shaft is a very reliable engine.

[biffer]

True enough. An older engine. Now days you have different outboards of the same make and hp. Years ago just the one. They are making them too gimmicky and trying to squeeze too much out of them. They say for instance 300 hp blah blah blah but won't guarantee it on a race boat or sometimes even if used commercially. It can either produce 300hp or it can't. Whats the difference of what boats it's on unless it can't cope with fair use

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[BogMonster]

Originally Posted by biffer

They say for instance 300 hp blah blah blah but won't guarantee it on a race boat or sometimes even if used commercially. It can either produce 300hp or it can't. Whats the difference of what boats it's on unless it can't cope with fair use

I don't think that is entirely fair because it depends what it is designed for and leisure/commercial are very different uses.

A big tractor engine will produce its rated power output at rated rpm chugging around a field all day long 50 weeks a year and probably not go wrong, a car engine if you do the same and run it at rated power will probably blow up fairly quickly! Our 70hp Case IH tractor has about a 4 litre engine in it IIRC, and a 4 litre engine in a car would produce what, up around 300hp these days maybe a lot more depending on tune?

Similar sort of thing with boat engines. The 10m Halmatic commercial launch at work has 6 litre Mermaid diesels producing 180hp and they will do that all day and last 10,000 hours or more because they are big and lazy and vastly over engineered for the power output. My E-TEC produces nearly that at 150hp out of something that weighs about 20% of the weight of the diesel, so it can fit in a lightweight boat and be bloody good fun but it won't do 10,000 hours (and neither will I). But if you dumped about a ton of Mermaid in the blunt end of my Vipermax it would probably sink

At the other extreme I'm sure you could get a six litre diesel to produce about 1000hp if you were tractor pulling, but I bet it wouldn't last 10,000 hours...

Horses for courses ... and I'd say outboards are primarily designed as leisure engines? That gives a sensible cost / weight / performance / lifespan / reliability compromise, because you can't have all of those.

[biffer]

Originally Posted by BogMonster

I don't think that is entirely fair because it depends what it is designed for and leisure/commercial are very different uses.

A big tractor engine will produce its rated power output at rated rpm chugging around a field all day long 50 weeks a year and probably not go wrong, a car engine if you do the same and run it at rated power will probably blow up fairly quickly! Our 70hp Case IH tractor has about a 4 litre engine in it IIRC, and a 4 litre engine in a car would produce what, up around 300hp these days maybe a lot more depending on tune?

Similar sort of thing with boat engines. The 10m Halmatic commercial launch at work has 6 litre Mermaid diesels producing 180hp and they will do that all day and last 10,000 hours or more because they are big and lazy and vastly over engineered for the power output. My E-TEC produces nearly that at 150hp out of something that weighs about 20% of the weight of the diesel, so it can fit in a lightweight boat and be bloody good fun but it won't do 10,000 hours (and neither will I). But if you dumped about a ton of Mermaid in the blunt end of my Vipermax it would probably sink

At the other extreme I'm sure you could get a six litre diesel to produce about 1000hp if you were tractor pulling, but I bet it wouldn't last 10,000 hours...

Horses for courses ... and I'd say outboards are primarily designed as leisure engines? That gives a sensible cost / weight / performance / lifespan / reliability compromise, because you can't have all of those.

your post is mainly my point, an outboard is rated at 300hp at full rev's, you need to put it in a boat where the rev's are achievable, great, put it say on a vipermax and blast it about for as long as you can, enter a race and your warranty goes out the window, same boat same rev's same fella driving it, what are they not telling us
the halmatic mermaid lump was from a ford lorry originally and will go up to about 250hp with intercooler etc, you could put that in loads of different boats including displacement, just change the gearbox ratio's, you still have the same hp but you're swinging a much larger prop at slower speed in a much larger boat, you can't do this with an outboard agreed which is probaly why you don't find many commercially

[wavelength]

which is probaly why you don't find many commercially

nowt to do with Biffer's point but using petrol o/bs in a work environment can be a nightmare. Petrol is usually unavailable in a commercial dock and rarely in a marina. So that means trips to the local supermarket with jerrycans, which has its own problems. And doing that delivering a workboat to a site via remote docks/marinas en-route is just another headache to contend with along with weather, deadlines etc.
Some commercial docks completely prohibit the use of any petrol powered vessels in their dock, and mention refuelling petrol with cans and they start to reach for the heart tablets!

[9D280]

Had a few Museums on my transoms over the years..... so, in no particular order:

1972 Johnson 25.
Bought it running like a dog. Once tuned & running, it would continually jump out of gear at the slightest provcation - turns out the dog clutch teeth were found to be worn to approx 45 degrees. One replacement set of gears & dog later and other than a cam roller dropping off last year which basically meant it drove a bit like putting a stop on the throttle at about 80% open (easily fixed by a few tuns of the adjuster screw to take up the slack for the trip home) and it's never missed a beat in 10 years eve nrunning on old fuel.

1993 Suz 25.
Only major failing was the throttle angle sensor. Only thing that did was mean it wouldn't do much above 1500rpm. Still got me home tho'. £150 (!!) of new sensor later.....

1975-ish Yam55 (twin pot)
Bought running, and continued to do so until the thermostat failed open (fairly common problem with thermostats) Only down side was that whilst replacing it I found the earth strap to the head had long broken, and the entire powerhead had turned to shortbread ((like I stripped a thread using nothing but a helicoll in the insertion tool!). Decidced to cut losses at that point. and bought.....

19canteen Merc Clamshell.
Well. This one's previous owner would appear to have tried to adjust everything to make it run better. Had he or she just checked the HT leads and found one of them had un- crimped itself at the coil end.....

One new set of HT leads later & it ran like a dream for about 10 mins until the spark avance stop screw locknut shook loose and the rest is history. What I did find during the rebuild was the standard problem of the early clamshells - top piston had been cooked and eroded by a lean mix and "right on the edge" spark advance. The rebuild has been fitted with MK2(3?) pistons, bigger jet in the top carb, revised spark advance, new water pump & various other mods that the later engines got.
So the bottom line is be a bit wary of the older ones unless you know their history.

[ben tye]

I have used outboards from most manufactures, working in some fairly backward parts of the world I have found the kiss of death for outboards is bad mechanics. I dread anything more then a regular service as I know the days of reliability are far behind. Not sure if other members agree but I think regular use of an engine is better then occasional trips out. I teach sailing and our engines are on all day everyday of the year and last for years. To be fair we never run them particularly hard.
Most problems I have experienced have been due to contaminated fuel. We try to keep tank full to avoid sucking up the sludge and reduce condensation in the tanks. In areas with suspect fuel we use a filter funnel to take the strain of the primary filters. Always amazed how people will spend thousands on a new engine but scrimp on changing filters, plugs, anodes and oil etc.
Trying to determine the reliability of an engine based on engine hours is a difficult thing because it is almost impossible to determine how it has been treated

[Poly]

Originally Posted by Channel Ribs

It has been suggested elsewhere that second hand engines are more prone to critical failure at sea than new ones, irrespective of fuel system or electrical installation.

I don't understand the hypothesis.

Their seems to be some logic (which may or may not be right) to these statements:

- an engine with a poor service history may be more likely to fail than a well maintained one
- modern outboards are more reliable than the used to be
- engine problems become more likely with age/hours/use/wear and tear
- simpler technology used to mean less to go seriously wrong (and easier to fix at sea)
- a "used" engine has been tested, a brand new engine is "unknown" - typical product failure curve will have a "peak" at the start - then a period of reliability, then wear related failures start to happen.

So unless your idea is that people keep good reliable engines, and sell on dodgy stuff then I don't see why a second hand engine per se is more likely to fail than an equivalent new engine.